1. Field of the Invention
This invention relates to a ventilated roofing structure, more particularly to a naturally ventilated roofing structure.
2. Description of the Related Art
Referring to FIG. 1, a conventional attic ventilation structure 11 is adapted to be mounted on a roof of a building with two base panels 111, and includes two support panels 112 extending upwardly from the base panels 111, and two roof panels 113 respectively fastened to the support panels 112 and spaced apart from the support panels 112 to respectively form two vent ports 115. Thus, heat inside the building can be exhausted out of the building through a ventilation opening 114 formed in the base panels 111 and the vent ports 115 by the combined effect of wind and thermal buoyancy forces. However, rainwater may splatter and enter the building through the vent ports 115, as indicated by hollow arrows in FIG. 1.
Referring to FIG. 2, another conventional ventilation device 12 is shown to include a base wall unit 121, a side wall unit 122, a roofing panel unit 123, and a water collecting tank 124. The base wall unit 121 includes two base panels 125 which are connected to each other at upper ends thereof and which cooperatively define a communicating opening 126. The side wall unit 122 is disposed on the base panels 125, and includes two side panels 128 that extend uprightly and two tilt panels 129 that extend toward each other. The roofing panel unit 123 is secured on the side wall unit 122, and includes a roof panel 100 which cooperates with the tilt panels 129 to define an S-shaped first ventilating duct 101. The water collecting tank 124 is disposed below the communicating opening 126, and cooperates with the base panels 125 to define an S-shaped second ventilating duct 102. Heat (as indicated by the dash arrows in FIG. 2) inside a building can be exhausted through the S-shaped second ventilating duct 102 and the S-shaped first ventilating duct 101. Besides, rainwater (as indicated by the hollow arrows in FIG. 2) which enters via the first ventilating duct 101 may fall into the water collecting tank 124 through the communicating opening 126. However, since the heat is exhausted along long and curved paths defined by the first and second ventilating ducts 101, 102, the heat dissipation effect is not satisfactory. In addition, by provision of the tilt panels 129 that project from the side panels 128, the structure of the conventional ventilation device 12 is weak and complicated, so that it is liable to be destroyed by strong winds and is costly to fabricate.
Referring to FIG. 3, still another conventional ventilation device 13 is shown to include an upright panel 131 and an eave panel 132. The upright panel 131 is configured to form part of a wall of a building, and has a ventilation window 133. The eave panel 132 is secured to an upper portion 134 of the upright panel 131 above the ventilation window 133 for baffling rainwater. However, rainwater may splatter and enter the building through the ventilation window 133, as indicated by hollow arrows in FIG. 3.